Polar bears come from Ireland, scientists claim

Although polar bears now live in the frozen wastes of the Arctic at the top of the world, scientists now think the mother of all polar bears was… Irish.

Celtic: A polar bear

Their ancestors interbred with brown bears when climate change led to occasional overlaps in their habitats in ancient Ireland 20,000 to 50,000 years ago, a genetic study has shown.

The cross-species mating led to maternal DNA from brown bears to be introduced into polar bears, which became âfixedâ in the species about 50,000 years ago. The finding overturns previous theories that the genetic material came from forebears that lived on several Alaskan islands 14,000 years ago, according to researchers in the US and Ireland.

Study co-author Beth Shapiro, of Penn State University, said: âThe bottom line is that the two species bumped up against one another for extended periods of time on different occasions, sharing both habitats and genes.â

While polar bears are expert swimmers adapted to an Arctic lifestyle and brown bears are climbers who prefer living in mountains and valleys, the two species interbred on âmanyâ occasions over the last 100,000 years.

âWhenever they come into contact, there seems to be little barrier to their mating,â said Ms Shapiro.

She said modern day changes in the Arctic climate such as melting glacial ice and rising sea levels has led to sightings of several adult hybrid bears in the last five years. Those cross-breeds could have a role to play in the survival of certain species.

She said the findings could also help conservation strategies for the dwindling population of polar bears today.